Tracie Egan Morrissey

Did you know that panda bears do headstands when they pee? It's not a circus trick or some weird, depressed captive behavior, but actually part of their scent-based mating ritual. With pandas being endangered, it's crucial for those in the wild to find each other. And so they go around, rubbing their bodies on trees and peeing all over the place. Their urine contains some kind of stinky secretion that communicates their sex and age. And the higher up off the ground, the better, as it maximizes their odor field. So male pandas do handstands and shoot their pee backwards.

According to a study published in the journal Animal Behaviour, pandas are very deliberate with their scent-marking because they have a lack of energy, due to a poor diet of strictly bamboo, which only contains little more energy than is needed to consume it. "We are not surprised that pandas are efficient with their use of chemo-signals, as mounting evidence suggests that many aspects of giant panda life history are constrained by their energetically poor diet," said researchers. So basically, male pandas are lazy and want to do as little as possible when it comes to wooing females.